U.S. patent application number 14/397741 was filed with the patent office on 2015-04-16 for magnet orientation and positionging system, method and apparatus.
This patent application is currently assigned to Vastostar Inc.. The applicant listed for this patent is Vastostar Inc.. Invention is credited to Paul L. Erickson, Mark G. Frantz, Roger W. Frantz, Todd C. Jean.
Application Number | 20150101187 14/397741 |
Document ID | / |
Family ID | 49758905 |
Filed Date | 2015-04-16 |
United States Patent
Application |
20150101187 |
Kind Code |
A1 |
Erickson; Paul L. ; et
al. |
April 16, 2015 |
MAGNET ORIENTATION AND POSITIONGING SYSTEM, METHOD AND
APPARATUS
Abstract
An apparatus (100) for orienting magnetic elements (14) for
assembly on a flexible elongated core member (12) includes a plate
(104) for supporting the magnetic elements (14). A plurality of
magnetic positioning elements (150) are secured to the plate (104)
and are configured to position and orient the magnetic elements
(14) to facilitate assembly of the elements (14) on the core member
(12).
Inventors: |
Erickson; Paul L.;
(Eastlake, OH) ; Frantz; Roger W.; (Mentor,
OH) ; Jean; Todd C.; (Perry, OH) ; Frantz;
Mark G.; (Shelter Island, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vastostar Inc. |
Mentor |
OH |
US |
|
|
Assignee: |
Vastostar Inc.
Mentor
OH
|
Family ID: |
49758905 |
Appl. No.: |
14/397741 |
Filed: |
June 14, 2013 |
PCT Filed: |
June 14, 2013 |
PCT NO: |
PCT/US2013/045840 |
371 Date: |
October 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61660346 |
Jun 15, 2012 |
|
|
|
Current U.S.
Class: |
29/729 ;
29/700 |
Current CPC
Class: |
H01F 7/0221 20130101;
B23P 19/001 20130101; B23P 11/00 20130101; Y10T 29/53 20150115;
Y10T 29/5313 20150115 |
Class at
Publication: |
29/729 ;
29/700 |
International
Class: |
B23P 11/00 20060101
B23P011/00 |
Claims
1. An apparatus for orienting magnetic elements for assembly on a
flexible elongated core member, the apparatus comprising: a plate
for supporting the magnetic elements; and a plurality of magnetic
positioning elements secured to the plate and configured to
position and orient the magnetic elements to facilitate assembly on
the core member.
2. The apparatus recited in claim 1, wherein the plate comprises a
channel recessed into a top surface of the plate, the positioning
elements being configured to magnetically attract and position the
magnetic elements in the channel.
3. The apparatus recited in claim 2, further comprising pockets for
receiving the positioning elements, the pockets being recessed into
a bottom surface of the plate opposite the top surface, the pockets
being arranged to extend along a path that is parallel with the
path of the channel.
4. The apparatus recited in claim 2, further comprising pockets
recessed into a bottom surface opposite the work surface, the
positioning elements being secured in the pockets.
5. The apparatus recited in claim 4, wherein the plate is a top
plate, the apparatus further comprising a base plate attachable to
the top plate to conceal and maintain the positioning elements in
the pockets.
6. The apparatus recited in claim 2, wherein the core member
comprises a guidewire core and the magnetic elements comprise
magnetic beads, the positioning elements positioning and orienting
the beads for receiving the guidewire core.
7. The apparatus recited in claim 6, wherein the channel is
configured to receive spacer elements between the magnetic
elements, the spacer elements being configured to receive the
guidewire core and to space the magnetic elements along the
guidewire.
8. The apparatus recited in claim 7, wherein the spacer elements
comprise cylindrical coil spring spacers.
9. The apparatus recited in claim 7, wherein the central apertures
of the spacer elements are axially aligned with throughbores of the
magnetic beads when the spacer elements are received in the
channel.
10. The apparatus recited in claim 7, wherein the spacers are
constructed of one of a ferromagnetic material and a
non-ferromagnetic material.
11. The apparatus recited in claim 2, further comprising a cover
that is receivable by the plate, the cover comprising a channel
that is presented toward the top surface and coextensive with the
channel in the plate, the coextensive channels defining a
cylindrical space that is adapted to guide the core member through
the magnetic elements positioned in the cylindrical space.
12. The apparatus recited in claim 11, wherein the cover is made of
an optically clear plastic.
13. The apparatus recited in claim 11, wherein cover serves to help
maintain the positions of the beads and spacers so that they do not
become dislodged by the insertion of the core.
14. The apparatus recited in claim 2, wherein the channel extends
the entire length of the plate through first and second ends of the
plate.
15. The apparatus recited in claim 1, wherein the positioning
elements are arranged with like poles adjacent to each other.
16. The apparatus recited in claim 1, wherein the magnetic elements
comprise at least one of permanent magnets, ferromagnetic elements,
and ferrimagnetic elements.
17. The apparatus recited in claim 1, wherein the magnetic elements
comprise hollow cylindrical beads, the apparatus being adapted to
guide the core member through the beads.
18. The apparatus recited in claim 1, wherein the positioning
elements comprise permanent magnets.
19. The apparatus recited in claim 1, wherein the positioning
elements comprise electromagnets.
20. The apparatus recited in claim 19, wherein the electromagnets
could be electrically wired and/or switched so that the magnetic
poles of each electromagnet are selectable, so that the apparatus
300 can adapt to a desired guidewire configuration.
21. The apparatus recited in claim 1, wherein the positioning
elements comprise portions of a magnetic strip of material.
22. The apparatus recited in claim 21, wherein the strip includes a
plurality of teeth that are spaced longitudinally along a
lengthwise extending edge of the strip, each tooth defining a
positioning element.
23. The apparatus recited in claim 22, wherein the teeth are
defined by a series of recesses that extend into the edge of the
strip.
24. The apparatus recited in claim 22, wherein the plate includes a
plurality of angled slots that are recessed into a top surface of
the plate.
25. The apparatus recited in claim 24, wherein each angled slot has
a first end flush with the top surface of the plate, the angled
slot extending into the plate at an angle terminating at a second
end at an intersection with an end wall defined by the slot.
26. The apparatus recited in claim 25, wherein the magnetic strip
is secured to the plate so that the teeth are positioned between
the angled slots and extend above the top surface of the plate.
27. The apparatus recited in claim 26, wherein the teeth position
the beads on the top surface between the angled slots.
28. The apparatus recited in claim 27, wherein the slots are
adapted to receive spacing elements and position the spacing
elements between the magnetic elements.
29. The apparatus recited in claim 1, wherein magnetic elements are
selected to be strong enough to provide the desired orientation of
the beads, but not so strong as to risk damaging the guidewire
during removal from the apparatus.
Description
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 61/660,346, filed on Jun. 15, 2012.
SUMMARY
[0002] The invention relates to a system, method and apparatus to
allow for the efficient assembly of a single magnet or multiple
magnets, with or without additional parts. According to one aspect,
the invention relates to a method of orienting the magnetic poles
and position of a magnet(s), and optionally other element(s) in
combination with the magnet(s). The method includes the use of a
propositioned magnet(s) or ferromagnetic/ferrimagnetic material in
a fixture that mates with the magnet(s)/element(s) to be oriented
and positioned. According to another aspect, the invention relates
to an apparatus that has retention slots or other means to maintain
the position and pole orientation of a magnet(s) or position of a
ferromagnetic/ferrimagnetic material in relation to a second
magnet(s), and optionally other element(s). Such apparatus may be a
multi-level fixture with prepositioned magnet(s) on one level and
the magnet(s)/element(s) to be oriented and positioned on a second
mating level. Alternatively, the fixture may locate the
magnet(s)/element(s) to be oriented and positioned on the same
plane as the prepositioned magnet(s). The apparatus may also allow
for the introduction of a securing means to hold such
magnet(s)/element(s) oriented and positioned once removed from the
fixture.
[0003] According to one aspect of the invention, an apparatus for
orienting magnetic elements for assembly on a flexible elongated
core member includes a plate for supporting the magnetic elements.
A plurality of magnetic positioning elements are secured to the
plate and are configured to position and orient the magnetic
elements to facilitate assembly of the elements on the core
member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The invention may be best understood by reference to the
following description taken in conjunction with the accompanying
drawing figures in which:
[0005] FIG. 1 is a perspective view illustrating example
configuration of an article of manufacture comprising a core member
with a plurality of elements affixed thereto;
[0006] FIG. 2 is a perspective view illustrating an apparatus for
orienting and positioning elements in an article of manufacture,
such as the article of manufacture illustrated in FIG. 1, according
to an embodiment of the invention;
[0007] FIG. 3 is a perspective view illustrating a bottom surface
of the apparatus of FIG. 2;
[0008] FIG. 4 is a magnified perspective view illustrating a
portion of the bottom surface of the apparatus shown in FIG. 3;
[0009] FIG. 5 is a further magnified perspective view illustrating
a portion of the bottom surface of the apparatus shown in FIGS. 3
and 4;
[0010] FIG. 6 is a magnified perspective view illustrating an
element positioning function of a portion of the apparatus;
[0011] FIG. 7 is a magnified sectional view illustrating the
element positioning function of the portion of the apparatus;
[0012] FIG. 8 is a magnified perspective view illustrating the
assembly of an article of manufacture, such as the article
illustrated in FIG. 1, using the apparatus;
[0013] FIG. 9 is a magnified sectional view illustrating the
assembly of the article of manufacture using the apparatus;
[0014] FIG. 10 is a magnified view from a different perspective
illustrating the assembly of the article of manufacture using the
apparatus;
[0015] FIG. 11 is a perspective view illustrating the apparatus
with a cover assembled thereto;
[0016] FIG. 12 is a magnified sectional view illustrating the
assembly of an article of manufacture, such as the article of
manufacture illustrated in FIG. 1, using the apparatus of FIG.
11;
[0017] FIG. 13 is the perspective view of the apparatus shown in
FIG. 11, with the cover shown translucent in order to illustrate
the assembly of the article of manufacture;
[0018] FIG. 14 is a magnified sectional view illustrating the
assembly of the article of manufacture using the apparatus of FIG.
11;
[0019] FIG. 15 is a perspective view illustrating an apparatus for
orienting and positioning elements in an article of manufacture,
such as the article of manufacture of FIG. 1, according to a second
embodiment of the invention;
[0020] FIG. 16 is a perspective view of the apparatus of FIG. 15
with a portion removed;
[0021] FIG. 17 is a perspective view of the apparatus of FIG. 16
with a portion magnified to show the detail of its
construction;
[0022] FIG. 18 is a perspective view of a portion of the apparatus
illustrated in FIG. 15;
[0023] FIG. 19 is a magnified perspective view of a portion of the
apparatus illustrated in FIG. 18;
[0024] FIG. 20 is a magnified perspective view of a portion of the
apparatus illustrated in FIG. 15;
[0025] FIG. 21 is a top plan view illustrating the assembly of an
article of manufacture using the apparatus of FIG. 15;
[0026] FIG. 22 is a magnified perspective, partially sectional view
of a portion of the apparatus being used to assemble the article of
manufacture; and
[0027] FIG. 23 is a perspective view of the apparatus of FIG. 15
with a portion magnified to show the detail of its
construction.
DESCRIPTION
[0028] The invention relates to a system, method and apparatus for
orienting and positioning magnetic elements in an article of
manufacture. According to one example, the invention relates to a
method and apparatus for orienting and positioning magnetic
elements on a core member, such as a flexible elongated core
member. Referring to FIG. 1, the invention may, in one particular
example, relate to a method and apparatus for use in the
manufacture of a guidewire 10. The example guidewire of FIG. 1
includes a flexible elongated core member, core 12, upon which one
or more magnetic elements, permanent magnets 14 are mounted. In the
example of FIG. 1, the guidewire includes spacer elements in the
form of spring-like coiled spacers 16 positioned between the
magnets 14. According to one particular example, the guidewire 10
may be a portion of a medical device in which the guidewire is
advanced through occlusions in a body lumen. In this example, it is
a lead or distal end portion 20 of the guidewire 10 that is fit
with the magnets 14 and spacers 16.
[0029] The guidewire 10 of FIG. 1 may be any conventional guidewire
used in medical applications.
[0030] According to one particular example, the diameter of the
proximal shaft and diameter of the spring coil distal tip are
0.014''. In this example, the diameter of the magnet/spacer section
of the core 12 is in the range of 0.014 to 0.016''. The
magnet-to-magnet period is 2 mm. In this example, the length of the
magnets 14 is in the range of about 1.0 to 1.5 mm, for example 1.4
mm.
[0031] The spacers 16 could have multiple designs. For example, the
illustrated spring coil spacers 16 could have alternative
configurations, such as plastic or metal solid tubes, plastic or
metal spiral cut tubes, or overmolded plastic. Any suitable metal
could be used, such as stainless steels, cobalt-based alloys (e.g.,
MP35N or Elgiloy), platinum or platinum alloys, titanium or
titanium alloys, and nitinol.
[0032] The magnets 14 and spacers 16 can be bonded to the core wire
with any suitable adhesive (eg: cyanoacrylate, epoxy, etc), then
jacketed with a thin heat shrink tube, e.g., polyester,
specifically polyethylene terephthalate (PET). A hydrophilic or
hydrophobic coating, alone or in some combination, can then be
applied to the spring coil distal tip (not shown) and the
magnet/spacer section.
[0033] FIG. 2 is a perspective view illustrating an apparatus 100
for orienting and positioning magnetic elements in an article of
manufacture. The apparatus 100 forms a portion, in the form of an
assembly fixture, of the system described herein. The apparatus 100
may, for example, be used to orient and position magnetic elements
on a core member, such as a flexible elongated core member.
According to one particular example, the apparatus 100 may be for
orienting and positioning magnetic elements on a guidewire, such as
the guidewire 10 of FIG. 1. In this description, reference may be
made to the X, Y, and Z axes or directions, which are shown in the
drawings.
[0034] In the example embodiment of FIG. 2, the apparatus 100
includes a base plate 102 and a top plate 104 that are connected or
bonded together in a suitable manner. Alternatively, the apparatus
100 could include additional layers of material (La, plates) or
could be constructed of a single layer/plate of material. According
to one example construction, the top plate 104 may be constructed
of, or be coated with, a polytetrafluoroethylene (PTFE) material,
which is available commercially as Teflon.RTM. from the E. I. du
Pont de Nemours and Company of Wilmington, Del. Any other suitable
material or combination of materials can be used. The materials for
the top plate and the base plate can be selected from materials
that are nonmagnetic. Nonmagnetic materials have little reaction to
magnetic fields (ie: they have a relative permeability close to
unity), and do not produce a magnetic field.
[0035] The apparatus 100 of the example embodiment of FIG. 2 has an
overall generally rectangular configuration. Alternative shapes
could be utilized. The top plate 104 includes a work area 110 that
is recessed (e.g., via machining or molding) into a top surface 112
of the plate (i.e., in the Y-direction). The work area 110 includes
a first portion 114, second portion 116, and third portion 118 that
are linearly arranged and extend from a first end 120 to an
opposite second end 122 of the top plate 104. The portions 114,
116, and 118 are contiguous and generally rectangular in form. The
first portion 114 is positioned at the first end 120 of the top
plate 104 and the third portion 118 is positioned at the second end
122 of the top plate, with the second portion 116 being positioned
therebetween. The first portion 114 is the largest of the work area
portions and forms the primary work area of the apparatus 100.
[0036] The work area 110 includes a work surface 124 that is
recessed into the top plate 104 and that extends throughout the
work area 110. The top plate 104 also includes a channel 130 that
is recessed (e.g., via machining or molding) further into the top
plate 104, i.e., recessed into or beneath the work surface 124. The
channel 130 extends the entire length of the top plate 104,
extending through the first end 120 and the second 122. The channel
130 is centered and extends linearly through each of the first 114,
second 116, and third 118 portions of the work area 110. The
channel 130 is centered on an axis 132 that essentially defines the
central, primary axis of the apparatus 100 in the X-direction.
Those skilled in the art will appreciate that the position and
shape of the channel 130 relative to other features may take on any
suitable arrangement. For example, the channel 130 may be offset
from the center of the work area 110. In another example, the
channel 130 may extend through each of the first 114, second 116,
and third 118 portions of the work area 110 along a curvilinear
path.
[0037] FIG. 3 is a perspective view illustrating a bottom surface
140 of the top plate 104. The top plate 104 includes a plurality of
means, in the form of pockets 142, for receiving elements, e.g.,
magnetic elements (such as permanent magnets, electromagnets,
ferromagnetic elements, ferrimagnetic elements), and securing the
elements to the top plate. The pockets 142 are recessed (e.g., via
machining or molding) into the bottom surface 140 and are arranged
linearly along an axis 144 that extends parallel to the axis 132
(see FIG. 2). In the illustrated embodiment, the axis 144 is
parallel to the axis 132 and is spaced from the axis 132 in the
Y-direction only.
[0038] Referring to the magnified views of FIGS. 4 and 5, the
pockets 142 are generally elongated and rectangular in form, each
having spaced, opposing side walls 160 and spaced, opposing end
walls 162 that extend transverse to the side walls. The pockets 142
each receive and support an element 150 (e.g., magnetic element) on
the base plate 102. In the example embodiment, the elements 150 are
permanent magnets, each of which has a generally cylindrical shape
(although any suitable shape may be used) and that are axially
magnetized (direction of magnetization is through their length).
The poles of each element 150 are indicated by a circled "N" for
north pole and a circled "S" for south pole. In the embodiment
illustrated in FIG. 5, the elements 150 are arranged with like
poles adjacent to each other. The elements 150 could, however, have
any desired arrangement, such as opposite poles adjacent to each
other or any combination of like or alternating polarities
positioned adjacent and/or facing to each other.
[0039] The pockets 142 each include end portions 164 that extend
transverse to the axis 144 beyond sidewalls 160. The end portions
164 are corner relief features and are the result of machining the
pockets 142 with a round cutting tool. End portions 164 may or may
not be present, depending on the manufacturing process used to
create pockets 142. The end portions 164 could, however, be used
advantageously to permit the insertion of a tool for installing,
removing, or positioning the elements 150 in the pockets 142. Once
the elements 150 are properly positioned, the base plate 102 is
attached to the top plate 104 (see FIG. 7) to conceal and maintain
the elements 150 in the pockets 142.
[0040] Referring to FIGS. 6 and 7, according to the illustrated
example embodiment, the apparatus 100 helps position and maintain
the position of magnetic elements (e.g., permanent magnets,
ferromagnetic elements, ferrimagnetic elements) or work pieces in
the channel 130. In the example embodiment, the elements positioned
in the channel 130 are magnetic (permanent magnet) cylindrical
beads 170, each of which has a central cylindrical throughbore that
extends along its length. The beads 170 are axially magnetically
polarized, i.e, the beads 170 are axially magnetized (magnetized
through their length)--north pole on one end and south pole on the
other. According to the invention, the elements 150, being embedded
in the base plate 102 and spaced adjacent and parallel to the
channel 130, position the beads 170 in the proper position and
orientation (polarity) in the channel. The magnetic elements 150
attract the magnetic beads 170 into the channel 130, position the
beads in the channel, and orient the beads with like polarities
adjacent to each other as shown in FIG. 7.
[0041] Advantageously, the elements 150 draw the beads 170 into the
channel 130 due to their inherent, mutually attractive magnetic
characteristics. The beads 170, due to their relatively small size
and their magnetic properties, would be difficult to position
manually. Determining which end of the beads have which polarity
and then assembling them in position adjacent to each other as
required would be extremely difficult due to the tendency of the
beads to attract and repel each other. The apparatus 100
advantageously overcomes these difficulties by implementing
elements 150 whose magnetic strength is sufficient to overcome the
repelling and/or attracting forces between the adjacent ends of the
beads 170. Thus, as shown in FIG. 7, the apparatus 100 is able to
maintain the beads 170 as shown, with like polarities facing each
other.
[0042] Those skilled in the art will appreciate that the position
and orientation of the elements 150 can be selected to produce a
corresponding desired position and orientation of the beads 170.
The apparatus 100 can position the beads at any orientation
relative to each other.
[0043] As shown in FIG. 7, the axis 132 along which the channel 130
extends is coaxial or substantially coaxial with the axes of the
beads 170. Additionally, the channel 130 may have an arcuate
cross-section that mates with the corresponding cylindrical outer
surfaces of the beads 170. Alternatively, the channel 130 may have
a rectilinear cross-section that mates in a tangential relationship
with the cylindrical outer surfaces of the beads 170. The shape,
cross-section, and configuration of the channel 130 can be designed
to accommodate elements of any shape, size, or configuration. The
shape, cross-section, and configuration of the channel 130, in
combination with the magnetic attraction of the elements 150 can
combine to position the elements/beads 170 in any desired manner.
Referring to FIGS. 8 to 10, the channel 130 may also receive
spacing elements 180, such as cylindrical coil spring spacers. The
spacers 180 have a coiled wire construction that leaves an open,
axially extending central aperture that extends along its length
and is generally centered on the axis 132. The central aperture of
the spacers 180 are thus axially aligned with the throughbores of
the beads 170.
[0044] The spacers 180 may be constructed of a ferromagnetic
material, such as stainless steel, or a non-ferromagnetic material,
such as Elgiloy. In the case where the spacers 180 are formed of a
ferromagnetic material, the spacers 180 are held in position in
channel 130 by the magnetic forces acting on the spacers 180. The
magnetic forces being a result of the magnetic fields produced by
elements 150 and beads 170. Those skilled in the art will
appreciate that the spacers 180 may take on any suitable
configuration. For example, if a coil/spring configuration is used,
the cross-section of the coiling wire may round, square,
rectangular or any other suitable shape. By way of another example,
the spacers 180, if implemented as coil/spring members, may be
wound with an open pitch or a closed pitch (i.e., tight wound). In
addition, the spacers may have a coil diameter that is constant
over the length of the coil/spring, or the coil diameter may vary
over the length of the coil/spring. Furthermore, the spacers 180
may take on other forms other than coils/springs. For example, the
spacing elements may be simple tubes (hollow cylinders) of any
suitable metal or plastic. Alternatively, the spacing elements may
be tubes where the tubular wall is cut through (by laser of other
suitable means) with a spiral or other pattern to provide the
element with the desired level of bending and axial stiffness.
Additionally, the spacers may be created by overmolding with a
plastic resin.
[0045] Referring to FIGS. 11 to 14, the apparatus 100 also includes
a cover 200. The cover 200 has a generally rectangular form and has
a width selected to mate with the width of the first portion 114 of
work area 110. The cover 200 also includes a channel 202 that
extends throughout its length. The cover 200 is configured such
that the channel 202 overlies and is generally coaxial with the
channel 130 when the cover is received in the first portion 114 of
the work area 110. In the illustrated embodiment, the channel 130
and the channel 202 combine to define a cylindrical space 204 that
extends along the axis 132. The cylindrical space 204 defined by
the channels 130 and 202 has a diameter that is selected to mate
with the core 12, magnetic elements 14, and spacer elements 16 of
the guidewire 10 of FIG. 1. The cover 200 can be made from a
nonmagnetic material so that it will not magnetically attract
magnetic beads 170 which would potentially disturb the positions of
magnetic beads 170 and spacers 180. According to one construction,
the cover 200 can be made of an optically clear plastic to permit
visualization of the underlying train of magnet beads 170 and
spacers 180. Those skilled in the art will appreciate that cover
200 may or may not include the channel 202, depending on the
cross-sectional shape and depth of the channel 130 in top plate
104.
[0046] To use the apparatus 100 to assemble the guidewire 10, the
magnetic elements 14, e.g., the magnetic beads 170, are placed in
the first portion 114 of the work area 110. The magnetic elements
150 embedded in the top plate 104 will attract the beads 170 into
the channel 130 and will position the beads with their magnetic
poles in the proper orientation, e.g., with like poles of adjacent
beads facing each other. Next, the spacer elements 16, i.e., the
spring/coil spacers 180, are inserted into the channel 130 between
the beads 170.
[0047] Next, the cover 200 is inserted into the first portion 114
of the work area 110. The channel 202 covers the aligned beads 170
and spacers 180. Next, the core 12 of the guidewire 10 is inserted
into the space 204 defined by the channels 130 and 202. In doing
so, the portion of the channel 130 extending through the second and
third portions 116 and 118 of the work area 110 help to guide the
core 12 into the space 204. While the core 12 is inserted, the
cover 200 serves to help maintain the positions of the bead 170 and
spacers 180 so that they do not become dislodged by the insertion
of the core. It will be appreciated by those skilled in the art
that the size of channels 130 and 202 relative to the size of the
guidewire components (e.g., core 12, magnets 14, spacers 16) may be
varied to provide any desired fit between the channels 130, 202 and
the guidewire components. For example, channels 130, 202 may be
sized slightly larger than the magnets 14 and spacers 16 to provide
a clearance fit such that the magnets 14 and spacers 16 are simply
trapped in between cover 200 and top plate 104 but not forcefully
clamped. Alternatively, the depth, in the Y-direction, of channels
130, 202 may be sized slightly smaller than the outer diameters of
magnets 14 and spacers 16 such that magnets 14 and spacers 16 are
clamped when the cover 200 is inserted into the first portion 114
of the work area 110 and held in place with a downward
(Y-direction) force.
[0048] Once the core 12 is inserted, the cover 200 can be removed,
leaving the assembled guidewire 10, which can then be removed from
the apparatus 10. Since the magnetic elements 14 (beads 170),
spacer elements (spring/coil spacers 180) and core 12 can be very
small diameter items, they can also be fragile. Because of this, it
may be desirable that the magnetic elements 150 not be so strong as
to risk damage to the guidewire 10 during removal. Therefore,
according to the invention, the magnetic elements 150 can be
selected to be strong enough to provide the desired orientation of
the beads 170, but not so strong as to risk damaging the guidewire
10 during removal from the apparatus 100. The desired level of
magnetic attractive force can be provided by varying any one of the
following parameters alone or in combination: magnet materials,
magnet grades, magnet sizes/shapes, and the distance (Y-direction)
between the magnetic beads 170 and the magnetic elements 150.
[0049] The apparatus 100 could be adapted or configured with
features for facilitating easy removal of the assembled guidewire
10. For example, the magnetic elements 150 could be embedded in a
layer separate from the top plate 104. The top plate 104 and this
separate layer holding the magnetic elements 150 could be held
together during assembly of the guidewire 10 and then separated
after assembly so that there is no magnetic resistance to removal
of the assembled guidewire. This could be achieved, for example, by
connecting the top plate 104 and the layer holding the magnetic
elements 150 via a sliding connection or a hinged connection.
[0050] By way of another example, the magnetic elements 150 could
be implemented as electromagnets. During assembly of the guidewire
10, the electromagnets could be activated with a supplied electric
current. While activated, the electromagnets would produce a
magnetic field. The magnetic field would act to position the beads
170 in the proper position and orientation (polarity) in the
channel 130. After assembly of beads 170 and spacers 180 onto core
12, the electromagnets could be deactivated by removing the
supplied electric current. When the electromagnets are in the
deactivated state, the electromagents no longer produce a magnetic
field, and the assembled guidewire 10 may be easily removed from
the apparatus 100 without undue magnetic resistance.
Advantageously, in this embodiment, the electromagnets could be
electrically wired and/or switched so that the magnetic poles of
each electromagnet are selectable, so that the apparatus 100 can
adapt to a desired guidewire configuration.
[0051] An apparatus 300 that forms a portion, in the form of a
bonding fixture, of the system described herein is illustrated in
FIGS. 15 to 23. Referring to FIG. 15, the apparatus 300 may, for
example be used to support, orient, and position magnetic elements
on a core member, such as a flexible elongated core member.
According to one particular example, the apparatus 300 may be for
supporting, orienting, and positioning magnetic elements on a
guidewire, such as the guidewire 10 of FIG. 1. Particularly, the
apparatus 300 may be used to support the guidewire 10 after the
magnets 14 and spacers 16 are assembled onto the core 12 using the
apparatus 100 of FIGS. 2 to 14. The apparatus 300 advantageously
supports the assembled elements of the guidewire 10 so that the
spacers 16 can be fixed to the core 12 by means, such as an
adhesive. In this description, reference may be made to the X, Y,
and Z axes or directions, which are shown in the drawings.
[0052] The apparatus 300 includes a base plate 302 and a top plate
304 that are connected or bonded together in a suitable manner.
Alternatively, the apparatus 300 could include additional layers of
material (i.e., plates) or could be constructed of a single
layer/plate of material. According to one example construction, the
top plate 304 may be constructed of, or be coated with, a
polytetrafluoroethylene (PTFE) material, which is available
commercially as Teflon.RTM. from the E. I. du Pont de Nemours and
Company of Wilmington, Del. Any other suitable nonmagnetic material
or combination of materials can be used.
[0053] The apparatus 300 of the example embodiment of FIG. 15 has a
generally rectangular configuration. Alternative shapes could be
utilized. Referring to FIG. 16, the top plate 304 includes a pocket
310 that is recessed (e.g., via machining or molding) into a top
surface 312 of the plate 304. The pocket 310 has a generally
elongated rectangular configuration designed to receive a
ferromagnetic/ferrimagnetic strip 320 that forms a portion of the
apparatus 300. The strip 320 has a generally elongated rectangular
configuration that is about the same as the configuration of the
pocket 310. The strip 320 therefore fits into the pocket 310.
[0054] The apparatus 300 also includes a channel 314 that is
recessed (Y-direction) into the top surface 312 of the top plate
304. The channel 314 is narrow and elongated in the X-direction,
extending along an axis 316 that is parallel to and generally
coincides with a lengthwise extending wall 332 of the pocket 310.
As shown in FIG. 15, the channel 314 may have a tapered
configuration for receiving and mating with a portion of the
guidewire core (see, e.g., FIG. 1). The channel 314 is much bigger
than the guidewire and serves to gradually direct the guidewire
down to the level of the workbench. The channel 314 thus can help
prevent the operator from accidentally folding the guidewire over
the edge of the fixture and damaging the wire.
[0055] Referring to the magnified view of FIG. 17, the top plate
304 includes a plurality of angled slots 330 that are recessed into
the top surface 312 of the top plate 304. The slots 330 are spaced
longitudinally (X-direction) adjacent to and along the wall 332 of
the pocket 310. Each slot 330 extends transverse (e.g.,
perpendicular, Z-direction) to the wall 332 and intersect the wall,
creating a rectangular opening at each intersection. Each slot 330
has a first end 334 flush with the top surface 312 of the top plate
304. The first end 334 extends into the top plate at an angle
(i.e., in a direction having both Y and Z components), terminating
at a second end 336 at the intersection with the wall 332.
[0056] Referring to FIGS. 18 and 19, the strip 320 includes a
plurality of teeth 340 that extend through the thickness
(Y-direction) of the strip. The teeth 340 are spaced longitudinally
(X-direction) adjacent to and along a lengthwise extending edge 342
of the strip 320. The teeth 340 are defined by a series of recesses
344 that extend into (Z-direction) the edge 342. The width
(X-direction) of the recesses 344 is selected so that the resulting
teeth 340 have a width (X-direction) that is about equal to the
width (X-direction) of the second ends 336 of the slots 330.
[0057] The spacing of the recesses 344 and the resulting teeth 340
is configured so that the recesses 344 extend across the second
ends 336 of corresponding slots 330 when the strip 320 is assembled
with the top plate 304 (see, e.g., FIG. 20). Similarly, end
surfaces 346 of the teeth 340 mate with corresponding portions of
the side wall 332 that extend between the slots 330. The dimensions
of the strip 320 and the pocket 310 may require close tolerances in
order to achieve this degree of alignment, especially considering
the small dimensions of the teeth 340 and slots 330. Alternatively,
accurate location of the recesses 344 relative to the slots 330 may
be achieved by many other suitable means such as dowel pins,
shoulder bolts, etc. As shown in FIG. 20, the strip 320 has a
thickness that is greater than the depth of the pocket 310. This
leaves an upper portion 350 of the end surfaces 346 of the teeth
340 exposed above the top surface 312 of the top plate 304.
[0058] Referring to FIGS. 21 to 23, the apparatus 300 helps
position and maintain the position of magnetic elements, e.g.,
permanent magnet elements or work pieces. In this embodiment, the
elements are permanent magnet cylindrical beads 370, each of which
has a central cylindrical throughbore that extends along its
length. The beads 370 are axially magnetically polarized, i.e., the
direction of magnetization of the beads 370 is along the length of
beads 370. According to the invention, the teeth 340, and
especially the exposed upper portions 350 of the end surfaces 346
of the teeth 340, serve as ferromagnetic/ferimagnetic elements that
are spaced along the axis 316 and along the abutting surfaces 332
and 346 of the pocket 310 and strip 320, respectively.
[0059] When the beads 370 are introduced onto the top surface 312
of the top plate 304, they are drawn to the exposed upper portions
350 of the teeth 340 due to the magnetic attraction between the
beads 370 and the teeth 340. The teeth 340 position the beads 370
in the desired manner, with the desired magnet-to-magnet spacing
distance controlled by the established tooth-to-tooth spacing
distance.
[0060] Those skilled in the art will appreciate that the position
and orientation of the teeth 340 can be selected to produce a
corresponding desired position and orientation of the beads 370.
The apparatus 300 can position the beads at any orientation
relative to each other.
[0061] In the embodiment of FIGS. 15 to 23, the slots 330 and
recesses 344 are adapted to receive spacing elements 380, such as
cylindrical coil spring spacers. The spacers 380 have a coiled wire
construction that leaves an open, axially extending central
aperture that extends along its length and is generally centered on
the axis 316. The central aperture of the spacers 380 are thus
axially aligned with the throughbores of the beads 370. The spacers
380 may be constructed of a ferromagnetic or a non-ferromagnetic
material.
[0062] To use the apparatus 300, an assembled or partially
assembled guidewire 10 is positioned on the top surface 312 of the
top plate 304. The magnetic beads 370 are attracted to the teeth
340, which positions the guidewire such that the magnet beads 370
are positioned against the teeth. This leaves the springs 380
situated within the gaps created by slots 330 and recesses 344.
Advantageously, the aligned slots 330 and recesses 344 leave the
spacers suspended on the core 12, with little or no touching of the
top plate 304 or strip 320. This allows for applying any adhesives
(e.g., glue) used to fix the spacers 380 and, thus, the beads 370
on the core 12 without the risk of the adhesives wicking to the top
plate 304 or strip 320 and bonding the assembled or partially
assembled guidewire 10 to the apparatus 300.
[0063] Since the magnetic elements 14 (beads 370), spacer elements
16 (e.g., spring/coil spacers 380) and core 12 can be very small
diameter items, they can also be fragile. Because of this, the
attractive force between the beads 370 and the
ferromagnetic/ferrimagnetic elements (upper portions 350 of teeth
340) cannot be so strong as to risk damage to the guidewire 10
during removal. Therefore, according to the invention, the
ferromagnetic/ferrimagnetic elements (upper portions 350 of teeth
340) are selected to be strong enough to provide the desired
orientation of the beads 370, but not so strong as to risk damaging
the guidewire 10 during removal from the apparatus 300.
[0064] The level of magnetic attractive force between the beads 370
and ferromagnetic/ferrimagnetic elements (upper portions 350 of
teeth 340) can be adjusted by modifying the size/shape of the
ferromagnetic/ferrimagnetic elements and/or selecting a material
for the strip 320 with either a higher or lower level of magnetic
permeability. For example, a material such as 1008 cold rolled
carbon steel has a high permeability and would produce a relatively
high magnetic attractive force. On the other hand a material such
as annealed 316 stainless steel, comparatively, has a much lower
permeability and would produce a much lower magnetic attractive
force. Other materials, such as full hard 302 stainless steel, have
a permeability in between 1008 carbon steel and annealed 316
stainless steel. Therefore, full hard 302 stainless steel would
produce a level of magnetic attractive force somewhere in between
1008 carbon steel and annealed 316 stainless steel.
[0065] Although the above described embodiment of apparatus 300
makes use of a ferromagnetic/ferrimagnetic member (strip 320) to
position the beads 370 and hold the guidewire 10, those skilled in
the art will appreciate that any suitable magnetic element(s) may
be used to position the beads 370 and hold the guidewire 10. For
example, one or more magnets could be used in place of or in
combination with one or more ferromagnetic/ferrimagnetic members.
The magnets used could be permanent magnets, electromagnets, or a
combination of permanent magnets and electromagnets. If
electromagnets are used, the electromagnets could be activated with
a supplied electric current during assembly of the guidewire 10.
While activated, the electromagnets would produce a magnetic field.
The magnetic field would act to position the beads 370 and hold the
guidewire 10 to facilitate one or more assembly steps. In this
example, the assembly step comprises bonding the beads 370 and the
spacers 380 to the core 12. After the one or more assembly steps
are completed, the electromagnets could be deactivated by removing
the supplied electric current. When the electromagnets are in the
deactivated state, the electromagnets no longer produce a magnetic
field, and the assembled guidewire 10 may be easily removed from
the apparatus 300 without undue magnetic resistance.
Advantageously, in this embodiment, the electromagnets could be
electrically wired and/or switched so that the magnetic poles of
each electromagnet are selectable, so that the apparatus 300 can
adapt to a desired guidewire configuration.
* * * * *